It is important to sex your rabbits in order to prevent unwanted pregnancies or injuries caused by teenage bucks fighting. It will also help you determine when you need to get your bunny neutered.
To sex your rabbit, turn your rabbit on its back and look at the underside, between the rear legs, near the base of the tail. While it is not always obvious, there are two holes here. To see the opening, you should gently use your fingers to move them apart. The opening closest to the tail is the anus. The genitals are at the opening closest to the belly.
Males / bucks
If your rabbit has not been neutered, the easiest way to sex them is to look for his testicles. They are near the genital opening and are flesh coloured. You may need to feel with your fingers as they are usually obscured by fur.
If your rabbit has been neutered, you will need to examine the genitals. Gently place a finger on each side of the opening and lightly apply pressure down. Next, examine what pops up. You can be sure it's a boy if a penis appears, or if you see a tube with a small opening at the top.
Females / does
Female rabbits pop out too, but are characterized as having a slit instead of a round opening. It is usually pink or may appear to have some dark red colouring.
Do not confuse the vulva for the penis, as it may pop out too. The vulva has a pyramid shape and a slit, which differentiates it from the penis.
If you are unsure how to sex your bunnies, you may consult your veterinarian.